Glyphosate-resistant weed problem extends to more species, more farms

The area of U.S. cropland infested with glyphosate-resistant weeds has expanded to 61.2 million acres in 2012, according to a survey conducted by Stratus Agri-Marketing. Nearly half of all U.S. farmers interviewed reported that glyphosate-resistant weeds were present on their farm in 2012, up from 34% of farmers in 2011. The survey also indicates that the rate at which glyphosate-resistant weeds are spreading is gaining momentum; increasing 25% in 2011 and 51% in 2012.

More About:

The area of U.S. cropland infested with glyphosate-resistant weeds has expanded to 61.2 million acres in 2012, according to a survey conducted by Stratus Agri-Marketing.

Nearly half (49%) of all U.S. farmers interviewed reported that glyphosate-resistant weeds were present on their farm in 2012, up from 34% of farmers in 2011. The survey also indicates that the rate at which glyphosate-resistant weeds are spreading is gaining momentum, increasing 25% in 2011 and 51% in 2012.

The Stratus Glyphosate Resistance Tracking study is conducted annually. It’s now in its third year. In 2012, Stratus completed interviews with nearly 3,000 farmers during the summer and fall.

“We asked farmers to share their experiences with glyphosate resistance on their farms and we’re clearly seeing the problem intensify,” explains Stratus Agri-Marketing vice president Kent Fraser. Increases were reported in most states but especially in the Midwest.

Not only are glyphosate-resistant weeds spreading geographically, the problem is also intensifying with multiple species now resistant on an increasing number of farms.

“There is a very high rate of resistance in the southern states like Georgia where 92% of growers reported having glyphosate-resistant weeds,” reports Fraser. “And we’re also seeing the problem intensify in the midwest. In Illinois, 43% of farmers reported having glyphosate-resistant weeds in 2012.”

Marestail (horseweed) was the weed species most commonly reported as resistant to glyphosate herbicides, followed by Palmer amaranth (pigweed). Other glyphosate-resistant weed species were also tracked in the study.

In 2012, 27% of U.S. farmers reported multiple glyphosate-resistant weeds on their farm, up from 15% in 2011 and 12% in 2010.

Related Articles

Partner Content

From the Field

Plan the right herbicide program

“We got spoiled when glyphosate controlled everything. We could skip the ‘pre-s’ and get by, but those days are over.” — Bob Hartzler, Iowa State University Extension weed specialist Click here to learn more.

Grower Success

Control a broad spectrum of weeds and grasses with SureStart® II herbicide

Weed to Watch

Marestail

Make scouting for marestail part of a routine. It can germinate year-round and is a high-anxiety weed across the Corn Belt.

Partner Spotlight

Spotlight on:

Flexible applications come rain or shine

By Luke Peters, corn herbicides product manager, Dow AgroSciences

Early season weed competition can steal moisture and essential nutrients from developing crops, which can significantly reduce yield potential. Timely herbicide applications are critical to control weeds when they are small and before they compete with crops.

As a result, growers need a plan that offers flexibility. That’s why they choose SureStart® II herbicide for flexible application options to fit their busy schedules and help overcome unexpected weather delays, such as untimely rain.

SureStart II can be applied from preplant to early postemergence, up to 11-inch-tall corn, with residual control that protects against emerging weeds for up to six weeks. Effective residual control provides a wide window for postemergence herbicide applications for control later in the season.

It also controls more than 60 broadleaf weeds and grasses, including difficult-to-control and herbicide-resistant species such as waterhemp, Palmer amaranth and giant ragweed.

We can’t go back in time, but this spring, we can use time more wisely. To learn more about the application flexibility of SureStart II, visit GetMoreTime.com.

®Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Durango DMA, SureStart and SureStart II are not registered for sale or use in all states. SureStart and SureStart II are not available for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions.